diff --git a/src/adclaw/meta/objects.py b/src/adclaw/meta/objects.py
index c50973c..7808839 100644
--- a/src/adclaw/meta/objects.py
+++ b/src/adclaw/meta/objects.py
@@ -159,15 +159,33 @@ def build_ad_set_payload(spec: CampaignSpec, campaign_id: str) -> dict[str, Any]
     if genders:
         targeting["genders"] = list(genders)
 
-    # Graph requires targeting on every ad set. Catching it here names the
-    # missing field; letting it through produces an opaque Meta rejection
-    # part-way into building the object chain.
+    # Graph requires targeting on every ad set. Checked before
+    # targeting_automation is added below, which is unconditional and
+    # would otherwise make `targeting` always non-empty and this guard
+    # dead code. Catching it here names the missing field; letting it
+    # through produces an opaque Meta rejection part-way into building the
+    # object chain.
     if not targeting:
         raise ValueError(
             "CampaignSpec.targeting is empty, so the ad set has no audience. "
             "Set at least one of countries, age_min, age_max or genders.",
         )
 
+    # Graph requires this on every ad set — code 100 / subcode 1870227,
+    # which is what stopped the connection test once optimisation_goal was
+    # fixed. Advantage+ Audience lets Meta expand delivery beyond the
+    # countries/age/gender actually specified. Defaulting to 0 (off) is the
+    # same call already made for bid_strategy: an ad set matches the
+    # audience it was told to, not whatever Meta additionally guesses.
+    # advanced.advantage_audience (0 or 1) overrides this per campaign.
+    advantage_audience = spec.advanced.get("advantage_audience", 0)
+    if advantage_audience not in (0, 1):
+        raise ValueError(
+            f"advanced.advantage_audience must be 0 or 1, got "
+            f"{advantage_audience!r}.",
+        )
+    targeting["targeting_automation"] = {"advantage_audience": advantage_audience}
+
     optimization_goal = spec.advanced.get("optimization_goal") or (
         DEFAULT_OPTIMIZATION_GOAL_BY_OBJECTIVE.get(
             spec.objective or "", DEFAULT_OPTIMIZATION_GOAL,
diff --git a/tests/test_meta_writes.py b/tests/test_meta_writes.py
index 03b735f..f04b6b9 100644
--- a/tests/test_meta_writes.py
+++ b/tests/test_meta_writes.py
@@ -448,6 +448,7 @@ def test_build_ad_set_payload_maps_targeting_and_budget():
         "age_min": 25,
         "age_max": 45,
         "geo_locations": {"countries": ["US", "CA"]},
+        "targeting_automation": {"advantage_audience": 0},
     }
     assert payload["optimization_goal"] == "LEAD_GENERATION"
     assert payload["billing_event"] == "IMPRESSIONS"
@@ -485,7 +486,10 @@ def test_build_ad_set_payload_requires_an_audience():
 def test_build_ad_set_payload_accepts_any_single_targeting_field():
     payload = build_ad_set_payload(_spec(targeting={"countries": ["IN"]}), "c1")
 
-    assert payload["targeting"] == {"geo_locations": {"countries": ["IN"]}}
+    assert payload["targeting"] == {
+        "geo_locations": {"countries": ["IN"]},
+        "targeting_automation": {"advantage_audience": 0},
+    }
 
 
 def test_build_ad_set_payload_accepts_allowlisted_optimization_goal():
@@ -705,6 +709,54 @@ def test_an_unknown_objective_falls_back_to_the_widest_goal():
     assert payload["optimization_goal"] == "LINK_CLICKS"
 
 
+# ---------------------------------------------------------------------------
+# Advantage+ Audience: the field Graph requires on every ad set's targeting
+# ---------------------------------------------------------------------------
+
+
+def test_targeting_automation_defaults_to_advantage_audience_off():
+    """Graph rejects an ad set whose targeting spec omits this — code 100 /
+    subcode 1870227, the failure that stopped the live connection test
+    once optimisation_goal was fixed.
+
+    Off by default for the same reason as bid_strategy: an ad set matches
+    the audience actually specified, not whatever Meta additionally
+    expands it to.
+    """
+    payload = build_ad_set_payload(_spec(), campaign_id="c1")
+
+    assert payload["targeting"]["targeting_automation"] == {
+        "advantage_audience": 0,
+    }
+
+
+def test_advantage_audience_can_be_turned_on():
+    spec = _spec(advanced={"advantage_audience": 1})
+
+    payload = build_ad_set_payload(spec, campaign_id="c1")
+
+    assert payload["targeting"]["targeting_automation"] == {
+        "advantage_audience": 1,
+    }
+
+
+def test_advantage_audience_rejects_anything_but_0_or_1():
+    spec = _spec(advanced={"advantage_audience": 2})
+
+    with pytest.raises(ValueError, match="advantage_audience"):
+        build_ad_set_payload(spec, campaign_id="c1")
+
+
+def test_an_empty_audience_is_still_refused_even_though_targeting_automation_is_always_set():
+    """targeting_automation is added unconditionally, so `targeting` is
+    never an empty dict any more. The no-audience guard has to run before
+    that, or this refusal silently stops firing."""
+    spec = _spec(targeting={})
+
+    with pytest.raises(ValueError, match="no audience"):
+        build_ad_set_payload(spec, campaign_id="c1")
+
+
 def test_an_explicit_optimisation_goal_still_wins():
     spec = _spec(
         objective="OUTCOME_TRAFFIC",